It was played in the ancient India by the name of MOKSHYA PATAMU. Mokshya is a metaphor for salvation achieved by doing good deeds and Patamu is a metaphor for taking rebirth in a lower form to pursue salvation. It was invented by Hindu spiritual teachers to teach children about the effects of good deeds as opposed to bad deeds. The Ladders represented good virtues such as Generosity, Faith, Humbleness, etc., and the Snakes represented evil virtues such as lust, anger, murder, theft, etc. The moral of the game was that a person could attain Moksha (Salvation) faster by doing good deeds whereas by doing evil one takes rebirth in lower forms of life (Patamu). The numbers of Ladders were lesser than the number of Snakes to remind people that treading the path of good is very difficult as compared to committing sins. Presumably, the number "100" represented Moksha (Salvation).
It has various versions and all of them are impressed by the ideals of the game. It is interesting to see how such games evolved with a much broader meaning than majority of people know today. Here we can see the importance of philosophy in our society. It provides us with a rational vision and we can get much out of what we consider obvious.